Upsize rudder pedal bushing plate mount holes to allow use of structural screws

It was decided to make the rudder pedal assemblies removeable for servicing (of the master cylinders in particular). To this end the 4.1mm holes holding the bushing retention plates were upsized to 4.2mm, allowing the use of MS27039 #8 structural screws (phillips head but shouldered, with locking nuts and appropriate washers)